ACPICA: Lindent
[linux-2.6.git] / drivers / char / n_r3964.c
1 /* r3964 linediscipline for linux
2  *
3  * -----------------------------------------------------------
4  * Copyright by 
5  * Philips Automation Projects
6  * Kassel (Germany)
7  * http://www.pap-philips.de
8  * -----------------------------------------------------------
9  * This software may be used and distributed according to the terms of
10  * the GNU General Public License, incorporated herein by reference.
11  *
12  * Author:
13  * L. Haag
14  *
15  * $Log: n_r3964.c,v $
16  * Revision 1.10  2001/03/18 13:02:24  dwmw2
17  * Fix timer usage, use spinlocks properly.
18  *
19  * Revision 1.9  2001/03/18 12:52:14  dwmw2
20  * Merge changes in 2.4.2
21  *
22  * Revision 1.8  2000/03/23 14:14:54  dwmw2
23  * Fix race in sleeping in r3964_read()
24  *
25  * Revision 1.7  1999/28/08 11:41:50  dwmw2
26  * Port to 2.3 kernel
27  *
28  * Revision 1.6  1998/09/30 00:40:40  dwmw2
29  * Fixed compilation on 2.0.x kernels
30  * Updated to newly registered tty-ldisc number 9
31  *
32  * Revision 1.5  1998/09/04 21:57:36  dwmw2
33  * Signal handling bug fixes, port to 2.1.x.
34  *
35  * Revision 1.4  1998/04/02 20:26:59  lhaag
36  * select, blocking, ...
37  *
38  * Revision 1.3  1998/02/12 18:58:43  root
39  * fixed some memory leaks
40  * calculation of checksum characters
41  *
42  * Revision 1.2  1998/02/07 13:03:34  root
43  * ioctl read_telegram
44  *
45  * Revision 1.1  1998/02/06 19:21:03  root
46  * Initial revision
47  *
48  *
49  */
50
51 #include <linux/module.h>
52 #include <linux/kernel.h>
53 #include <linux/sched.h>
54 #include <linux/types.h>
55 #include <linux/fcntl.h>
56 #include <linux/interrupt.h>
57 #include <linux/ptrace.h>
58 #include <linux/ioport.h>
59 #include <linux/in.h>
60 #include <linux/slab.h>
61 #include <linux/tty.h>
62 #include <linux/errno.h>
63 #include <linux/string.h>       /* used in new tty drivers */
64 #include <linux/signal.h>       /* used in new tty drivers */
65 #include <linux/ioctl.h>
66 #include <linux/n_r3964.h>
67 #include <linux/poll.h>
68 #include <linux/init.h>
69 #include <asm/uaccess.h>
70
71 /*#define DEBUG_QUEUE*/
72
73 /* Log successful handshake and protocol operations  */
74 /*#define DEBUG_PROTO_S*/
75
76 /* Log handshake and protocol errors: */
77 /*#define DEBUG_PROTO_E*/
78
79 /* Log Linediscipline operations (open, close, read, write...): */
80 /*#define DEBUG_LDISC*/
81
82 /* Log module and memory operations (init, cleanup; kmalloc, kfree): */
83 /*#define DEBUG_MODUL*/
84
85 /* Macro helpers for debug output: */
86 #define TRACE(format, args...) printk("r3964: " format "\n" , ## args)
87
88 #ifdef DEBUG_MODUL
89 #define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args)
90 #else
91 #define TRACE_M(fmt, arg...) do {} while (0)
92 #endif
93 #ifdef DEBUG_PROTO_S
94 #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
95 #else
96 #define TRACE_PS(fmt, arg...) do {} while (0)
97 #endif
98 #ifdef DEBUG_PROTO_E
99 #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
100 #else
101 #define TRACE_PE(fmt, arg...) do {} while (0)
102 #endif
103 #ifdef DEBUG_LDISC
104 #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
105 #else
106 #define TRACE_L(fmt, arg...) do {} while (0)
107 #endif
108 #ifdef DEBUG_QUEUE
109 #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
110 #else
111 #define TRACE_Q(fmt, arg...) do {} while (0)
112 #endif
113 static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
114 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
115 static void put_char(struct r3964_info *pInfo, unsigned char ch);
116 static void trigger_transmit(struct r3964_info *pInfo);
117 static void retry_transmit(struct r3964_info *pInfo);
118 static void transmit_block(struct r3964_info *pInfo);
119 static void receive_char(struct r3964_info *pInfo, const unsigned char c);
120 static void receive_error(struct r3964_info *pInfo, const char flag);
121 static void on_timeout(unsigned long priv);
122 static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
123 static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
124                 unsigned char __user * buf);
125 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
126                 int error_code, struct r3964_block_header *pBlock);
127 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
128                 struct r3964_client_info *pClient);
129 static void remove_client_block(struct r3964_info *pInfo,
130                 struct r3964_client_info *pClient);
131
132 static int r3964_open(struct tty_struct *tty);
133 static void r3964_close(struct tty_struct *tty);
134 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
135                 unsigned char __user * buf, size_t nr);
136 static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
137                 const unsigned char *buf, size_t nr);
138 static int r3964_ioctl(struct tty_struct *tty, struct file *file,
139                 unsigned int cmd, unsigned long arg);
140 static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
141 static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
142                 struct poll_table_struct *wait);
143 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
144                 char *fp, int count);
145
146 static struct tty_ldisc tty_ldisc_N_R3964 = {
147         .owner = THIS_MODULE,
148         .magic = TTY_LDISC_MAGIC,
149         .name = "R3964",
150         .open = r3964_open,
151         .close = r3964_close,
152         .read = r3964_read,
153         .write = r3964_write,
154         .ioctl = r3964_ioctl,
155         .set_termios = r3964_set_termios,
156         .poll = r3964_poll,
157         .receive_buf = r3964_receive_buf,
158 };
159
160 static void dump_block(const unsigned char *block, unsigned int length)
161 {
162         unsigned int i, j;
163         char linebuf[16 * 3 + 1];
164
165         for (i = 0; i < length; i += 16) {
166                 for (j = 0; (j < 16) && (j + i < length); j++) {
167                         sprintf(linebuf + 3 * j, "%02x ", block[i + j]);
168                 }
169                 linebuf[3 * j] = '\0';
170                 TRACE_PS("%s", linebuf);
171         }
172 }
173
174 /*************************************************************
175  * Driver initialisation
176  *************************************************************/
177
178 /*************************************************************
179  * Module support routines
180  *************************************************************/
181
182 static void __exit r3964_exit(void)
183 {
184         int status;
185
186         TRACE_M("cleanup_module()");
187
188         status = tty_unregister_ldisc(N_R3964);
189
190         if (status != 0) {
191                 printk(KERN_ERR "r3964: error unregistering linediscipline: "
192                                 "%d\n", status);
193         } else {
194                 TRACE_L("linediscipline successfully unregistered");
195         }
196 }
197
198 static int __init r3964_init(void)
199 {
200         int status;
201
202         printk("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
203
204         /*
205          * Register the tty line discipline
206          */
207
208         status = tty_register_ldisc(N_R3964, &tty_ldisc_N_R3964);
209         if (status == 0) {
210                 TRACE_L("line discipline %d registered", N_R3964);
211                 TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
212                         tty_ldisc_N_R3964.num);
213                 TRACE_L("open=%p", tty_ldisc_N_R3964.open);
214                 TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
215         } else {
216                 printk(KERN_ERR "r3964: error registering line discipline: "
217                                 "%d\n", status);
218         }
219         return status;
220 }
221
222 module_init(r3964_init);
223 module_exit(r3964_exit);
224
225 /*************************************************************
226  * Protocol implementation routines
227  *************************************************************/
228
229 static void add_tx_queue(struct r3964_info *pInfo,
230                          struct r3964_block_header *pHeader)
231 {
232         unsigned long flags;
233
234         spin_lock_irqsave(&pInfo->lock, flags);
235
236         pHeader->next = NULL;
237
238         if (pInfo->tx_last == NULL) {
239                 pInfo->tx_first = pInfo->tx_last = pHeader;
240         } else {
241                 pInfo->tx_last->next = pHeader;
242                 pInfo->tx_last = pHeader;
243         }
244
245         spin_unlock_irqrestore(&pInfo->lock, flags);
246
247         TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
248                 pHeader, pHeader->length, pInfo->tx_first);
249 }
250
251 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
252 {
253         struct r3964_block_header *pHeader;
254         unsigned long flags;
255 #ifdef DEBUG_QUEUE
256         struct r3964_block_header *pDump;
257 #endif
258
259         pHeader = pInfo->tx_first;
260
261         if (pHeader == NULL)
262                 return;
263
264 #ifdef DEBUG_QUEUE
265         printk("r3964: remove_from_tx_queue: %p, length %u - ",
266                 pHeader, pHeader->length);
267         for (pDump = pHeader; pDump; pDump = pDump->next)
268                 printk("%p ", pDump);
269         printk("\n");
270 #endif
271
272         if (pHeader->owner) {
273                 if (error_code) {
274                         add_msg(pHeader->owner, R3964_MSG_ACK, 0,
275                                 error_code, NULL);
276                 } else {
277                         add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
278                                 error_code, NULL);
279                 }
280                 wake_up_interruptible(&pInfo->read_wait);
281         }
282
283         spin_lock_irqsave(&pInfo->lock, flags);
284
285         pInfo->tx_first = pHeader->next;
286         if (pInfo->tx_first == NULL) {
287                 pInfo->tx_last = NULL;
288         }
289
290         spin_unlock_irqrestore(&pInfo->lock, flags);
291
292         kfree(pHeader);
293         TRACE_M("remove_from_tx_queue - kfree %p", pHeader);
294
295         TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
296                 pInfo->tx_first, pInfo->tx_last);
297 }
298
299 static void add_rx_queue(struct r3964_info *pInfo,
300                          struct r3964_block_header *pHeader)
301 {
302         unsigned long flags;
303
304         spin_lock_irqsave(&pInfo->lock, flags);
305
306         pHeader->next = NULL;
307
308         if (pInfo->rx_last == NULL) {
309                 pInfo->rx_first = pInfo->rx_last = pHeader;
310         } else {
311                 pInfo->rx_last->next = pHeader;
312                 pInfo->rx_last = pHeader;
313         }
314         pInfo->blocks_in_rx_queue++;
315
316         spin_unlock_irqrestore(&pInfo->lock, flags);
317
318         TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
319                 pHeader, pHeader->length,
320                 pInfo->rx_first, pInfo->blocks_in_rx_queue);
321 }
322
323 static void remove_from_rx_queue(struct r3964_info *pInfo,
324                                  struct r3964_block_header *pHeader)
325 {
326         unsigned long flags;
327         struct r3964_block_header *pFind;
328
329         if (pHeader == NULL)
330                 return;
331
332         TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
333                 pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
334         TRACE_Q("remove_from_rx_queue: %p, length %u",
335                 pHeader, pHeader->length);
336
337         spin_lock_irqsave(&pInfo->lock, flags);
338
339         if (pInfo->rx_first == pHeader) {
340                 /* Remove the first block in the linked list: */
341                 pInfo->rx_first = pHeader->next;
342
343                 if (pInfo->rx_first == NULL) {
344                         pInfo->rx_last = NULL;
345                 }
346                 pInfo->blocks_in_rx_queue--;
347         } else {
348                 /* Find block to remove: */
349                 for (pFind = pInfo->rx_first; pFind; pFind = pFind->next) {
350                         if (pFind->next == pHeader) {
351                                 /* Got it. */
352                                 pFind->next = pHeader->next;
353                                 pInfo->blocks_in_rx_queue--;
354                                 if (pFind->next == NULL) {
355                                         /* Oh, removed the last one! */
356                                         pInfo->rx_last = pFind;
357                                 }
358                                 break;
359                         }
360                 }
361         }
362
363         spin_unlock_irqrestore(&pInfo->lock, flags);
364
365         kfree(pHeader);
366         TRACE_M("remove_from_rx_queue - kfree %p", pHeader);
367
368         TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
369                 pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
370 }
371
372 static void put_char(struct r3964_info *pInfo, unsigned char ch)
373 {
374         struct tty_struct *tty = pInfo->tty;
375
376         if (tty == NULL)
377                 return;
378
379         if (tty->driver->put_char) {
380                 tty->driver->put_char(tty, ch);
381         }
382         pInfo->bcc ^= ch;
383 }
384
385 static void flush(struct r3964_info *pInfo)
386 {
387         struct tty_struct *tty = pInfo->tty;
388
389         if (tty == NULL)
390                 return;
391
392         if (tty->driver->flush_chars) {
393                 tty->driver->flush_chars(tty);
394         }
395 }
396
397 static void trigger_transmit(struct r3964_info *pInfo)
398 {
399         unsigned long flags;
400
401         spin_lock_irqsave(&pInfo->lock, flags);
402
403         if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
404                 pInfo->state = R3964_TX_REQUEST;
405                 pInfo->nRetry = 0;
406                 pInfo->flags &= ~R3964_ERROR;
407                 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
408
409                 spin_unlock_irqrestore(&pInfo->lock, flags);
410
411                 TRACE_PS("trigger_transmit - sent STX");
412
413                 put_char(pInfo, STX);
414                 flush(pInfo);
415
416                 pInfo->bcc = 0;
417         } else {
418                 spin_unlock_irqrestore(&pInfo->lock, flags);
419         }
420 }
421
422 static void retry_transmit(struct r3964_info *pInfo)
423 {
424         if (pInfo->nRetry < R3964_MAX_RETRIES) {
425                 TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
426                 pInfo->bcc = 0;
427                 put_char(pInfo, STX);
428                 flush(pInfo);
429                 pInfo->state = R3964_TX_REQUEST;
430                 pInfo->nRetry++;
431                 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
432         } else {
433                 TRACE_PE("transmission failed after %d retries",
434                          R3964_MAX_RETRIES);
435
436                 remove_from_tx_queue(pInfo, R3964_TX_FAIL);
437
438                 put_char(pInfo, NAK);
439                 flush(pInfo);
440                 pInfo->state = R3964_IDLE;
441
442                 trigger_transmit(pInfo);
443         }
444 }
445
446 static void transmit_block(struct r3964_info *pInfo)
447 {
448         struct tty_struct *tty = pInfo->tty;
449         struct r3964_block_header *pBlock = pInfo->tx_first;
450         int room = 0;
451
452         if ((tty == NULL) || (pBlock == NULL)) {
453                 return;
454         }
455
456         if (tty->driver->write_room)
457                 room = tty->driver->write_room(tty);
458
459         TRACE_PS("transmit_block %p, room %d, length %d",
460                  pBlock, room, pBlock->length);
461
462         while (pInfo->tx_position < pBlock->length) {
463                 if (room < 2)
464                         break;
465
466                 if (pBlock->data[pInfo->tx_position] == DLE) {
467                         /* send additional DLE char: */
468                         put_char(pInfo, DLE);
469                 }
470                 put_char(pInfo, pBlock->data[pInfo->tx_position++]);
471
472                 room--;
473         }
474
475         if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
476                 put_char(pInfo, DLE);
477                 put_char(pInfo, ETX);
478                 if (pInfo->flags & R3964_BCC) {
479                         put_char(pInfo, pInfo->bcc);
480                 }
481                 pInfo->state = R3964_WAIT_FOR_TX_ACK;
482                 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
483         }
484         flush(pInfo);
485 }
486
487 static void on_receive_block(struct r3964_info *pInfo)
488 {
489         unsigned int length;
490         struct r3964_client_info *pClient;
491         struct r3964_block_header *pBlock;
492
493         length = pInfo->rx_position;
494
495         /* compare byte checksum characters: */
496         if (pInfo->flags & R3964_BCC) {
497                 if (pInfo->bcc != pInfo->last_rx) {
498                         TRACE_PE("checksum error - got %x but expected %x",
499                                  pInfo->last_rx, pInfo->bcc);
500                         pInfo->flags |= R3964_CHECKSUM;
501                 }
502         }
503
504         /* check for errors (parity, overrun,...): */
505         if (pInfo->flags & R3964_ERROR) {
506                 TRACE_PE("on_receive_block - transmission failed error %x",
507                          pInfo->flags & R3964_ERROR);
508
509                 put_char(pInfo, NAK);
510                 flush(pInfo);
511                 if (pInfo->nRetry < R3964_MAX_RETRIES) {
512                         pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
513                         pInfo->nRetry++;
514                         mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
515                 } else {
516                         TRACE_PE("on_receive_block - failed after max retries");
517                         pInfo->state = R3964_IDLE;
518                 }
519                 return;
520         }
521
522         /* received block; submit DLE: */
523         put_char(pInfo, DLE);
524         flush(pInfo);
525         del_timer_sync(&pInfo->tmr);
526         TRACE_PS(" rx success: got %d chars", length);
527
528         /* prepare struct r3964_block_header: */
529         pBlock = kmalloc(length + sizeof(struct r3964_block_header),
530                         GFP_KERNEL);
531         TRACE_M("on_receive_block - kmalloc %p", pBlock);
532
533         if (pBlock == NULL)
534                 return;
535
536         pBlock->length = length;
537         pBlock->data = ((unsigned char *)pBlock) +
538                         sizeof(struct r3964_block_header);
539         pBlock->locks = 0;
540         pBlock->next = NULL;
541         pBlock->owner = NULL;
542
543         memcpy(pBlock->data, pInfo->rx_buf, length);
544
545         /* queue block into rx_queue: */
546         add_rx_queue(pInfo, pBlock);
547
548         /* notify attached client processes: */
549         for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
550                 if (pClient->sig_flags & R3964_SIG_DATA) {
551                         add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
552                                 pBlock);
553                 }
554         }
555         wake_up_interruptible(&pInfo->read_wait);
556
557         pInfo->state = R3964_IDLE;
558
559         trigger_transmit(pInfo);
560 }
561
562 static void receive_char(struct r3964_info *pInfo, const unsigned char c)
563 {
564         switch (pInfo->state) {
565         case R3964_TX_REQUEST:
566                 if (c == DLE) {
567                         TRACE_PS("TX_REQUEST - got DLE");
568
569                         pInfo->state = R3964_TRANSMITTING;
570                         pInfo->tx_position = 0;
571
572                         transmit_block(pInfo);
573                 } else if (c == STX) {
574                         if (pInfo->nRetry == 0) {
575                                 TRACE_PE("TX_REQUEST - init conflict");
576                                 if (pInfo->priority == R3964_SLAVE) {
577                                         goto start_receiving;
578                                 }
579                         } else {
580                                 TRACE_PE("TX_REQUEST - secondary init "
581                                         "conflict!? Switching to SLAVE mode "
582                                         "for next rx.");
583                                 goto start_receiving;
584                         }
585                 } else {
586                         TRACE_PE("TX_REQUEST - char != DLE: %x", c);
587                         retry_transmit(pInfo);
588                 }
589                 break;
590         case R3964_TRANSMITTING:
591                 if (c == NAK) {
592                         TRACE_PE("TRANSMITTING - got NAK");
593                         retry_transmit(pInfo);
594                 } else {
595                         TRACE_PE("TRANSMITTING - got invalid char");
596
597                         pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
598                         mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
599                 }
600                 break;
601         case R3964_WAIT_FOR_TX_ACK:
602                 if (c == DLE) {
603                         TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
604                         remove_from_tx_queue(pInfo, R3964_OK);
605
606                         pInfo->state = R3964_IDLE;
607                         trigger_transmit(pInfo);
608                 } else {
609                         retry_transmit(pInfo);
610                 }
611                 break;
612         case R3964_WAIT_FOR_RX_REPEAT:
613                 /* FALLTROUGH */
614         case R3964_IDLE:
615                 if (c == STX) {
616                         /* Prevent rx_queue from overflow: */
617                         if (pInfo->blocks_in_rx_queue >=
618                             R3964_MAX_BLOCKS_IN_RX_QUEUE) {
619                                 TRACE_PE("IDLE - got STX but no space in "
620                                                 "rx_queue!");
621                                 pInfo->state = R3964_WAIT_FOR_RX_BUF;
622                                 mod_timer(&pInfo->tmr,
623                                           jiffies + R3964_TO_NO_BUF);
624                                 break;
625                         }
626 start_receiving:
627                         /* Ok, start receiving: */
628                         TRACE_PS("IDLE - got STX");
629                         pInfo->rx_position = 0;
630                         pInfo->last_rx = 0;
631                         pInfo->flags &= ~R3964_ERROR;
632                         pInfo->state = R3964_RECEIVING;
633                         mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
634                         pInfo->nRetry = 0;
635                         put_char(pInfo, DLE);
636                         flush(pInfo);
637                         pInfo->bcc = 0;
638                 }
639                 break;
640         case R3964_RECEIVING:
641                 if (pInfo->rx_position < RX_BUF_SIZE) {
642                         pInfo->bcc ^= c;
643
644                         if (c == DLE) {
645                                 if (pInfo->last_rx == DLE) {
646                                         pInfo->last_rx = 0;
647                                         goto char_to_buf;
648                                 }
649                                 pInfo->last_rx = DLE;
650                                 break;
651                         } else if ((c == ETX) && (pInfo->last_rx == DLE)) {
652                                 if (pInfo->flags & R3964_BCC) {
653                                         pInfo->state = R3964_WAIT_FOR_BCC;
654                                         mod_timer(&pInfo->tmr,
655                                                   jiffies + R3964_TO_ZVZ);
656                                 } else {
657                                         on_receive_block(pInfo);
658                                 }
659                         } else {
660                                 pInfo->last_rx = c;
661 char_to_buf:
662                                 pInfo->rx_buf[pInfo->rx_position++] = c;
663                                 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
664                         }
665                 }
666                 /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
667                 break;
668         case R3964_WAIT_FOR_BCC:
669                 pInfo->last_rx = c;
670                 on_receive_block(pInfo);
671                 break;
672         }
673 }
674
675 static void receive_error(struct r3964_info *pInfo, const char flag)
676 {
677         switch (flag) {
678         case TTY_NORMAL:
679                 break;
680         case TTY_BREAK:
681                 TRACE_PE("received break");
682                 pInfo->flags |= R3964_BREAK;
683                 break;
684         case TTY_PARITY:
685                 TRACE_PE("parity error");
686                 pInfo->flags |= R3964_PARITY;
687                 break;
688         case TTY_FRAME:
689                 TRACE_PE("frame error");
690                 pInfo->flags |= R3964_FRAME;
691                 break;
692         case TTY_OVERRUN:
693                 TRACE_PE("frame overrun");
694                 pInfo->flags |= R3964_OVERRUN;
695                 break;
696         default:
697                 TRACE_PE("receive_error - unknown flag %d", flag);
698                 pInfo->flags |= R3964_UNKNOWN;
699                 break;
700         }
701 }
702
703 static void on_timeout(unsigned long priv)
704 {
705         struct r3964_info *pInfo = (void *)priv;
706
707         switch (pInfo->state) {
708         case R3964_TX_REQUEST:
709                 TRACE_PE("TX_REQUEST - timeout");
710                 retry_transmit(pInfo);
711                 break;
712         case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
713                 put_char(pInfo, NAK);
714                 flush(pInfo);
715                 retry_transmit(pInfo);
716                 break;
717         case R3964_WAIT_FOR_TX_ACK:
718                 TRACE_PE("WAIT_FOR_TX_ACK - timeout");
719                 retry_transmit(pInfo);
720                 break;
721         case R3964_WAIT_FOR_RX_BUF:
722                 TRACE_PE("WAIT_FOR_RX_BUF - timeout");
723                 put_char(pInfo, NAK);
724                 flush(pInfo);
725                 pInfo->state = R3964_IDLE;
726                 break;
727         case R3964_RECEIVING:
728                 TRACE_PE("RECEIVING - timeout after %d chars",
729                          pInfo->rx_position);
730                 put_char(pInfo, NAK);
731                 flush(pInfo);
732                 pInfo->state = R3964_IDLE;
733                 break;
734         case R3964_WAIT_FOR_RX_REPEAT:
735                 TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
736                 pInfo->state = R3964_IDLE;
737                 break;
738         case R3964_WAIT_FOR_BCC:
739                 TRACE_PE("WAIT_FOR_BCC - timeout");
740                 put_char(pInfo, NAK);
741                 flush(pInfo);
742                 pInfo->state = R3964_IDLE;
743                 break;
744         }
745 }
746
747 static struct r3964_client_info *findClient(struct r3964_info *pInfo,
748                 struct pid *pid)
749 {
750         struct r3964_client_info *pClient;
751
752         for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
753                 if (pClient->pid == pid) {
754                         return pClient;
755                 }
756         }
757         return NULL;
758 }
759
760 static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
761 {
762         struct r3964_client_info *pClient;
763         struct r3964_client_info **ppClient;
764         struct r3964_message *pMsg;
765
766         if ((arg & R3964_SIG_ALL) == 0) {
767                 /* Remove client from client list */
768                 for (ppClient = &pInfo->firstClient; *ppClient;
769                      ppClient = &(*ppClient)->next) {
770                         pClient = *ppClient;
771
772                         if (pClient->pid == pid) {
773                                 TRACE_PS("removing client %d from client list",
774                                          pid_nr(pid));
775                                 *ppClient = pClient->next;
776                                 while (pClient->msg_count) {
777                                         pMsg = remove_msg(pInfo, pClient);
778                                         if (pMsg) {
779                                                 kfree(pMsg);
780                                                 TRACE_M("enable_signals - msg "
781                                                         "kfree %p", pMsg);
782                                         }
783                                 }
784                                 put_pid(pClient->pid);
785                                 kfree(pClient);
786                                 TRACE_M("enable_signals - kfree %p", pClient);
787                                 return 0;
788                         }
789                 }
790                 return -EINVAL;
791         } else {
792                 pClient = findClient(pInfo, pid);
793                 if (pClient) {
794                         /* update signal options */
795                         pClient->sig_flags = arg;
796                 } else {
797                         /* add client to client list */
798                         pClient = kmalloc(sizeof(struct r3964_client_info),
799                                         GFP_KERNEL);
800                         TRACE_M("enable_signals - kmalloc %p", pClient);
801                         if (pClient == NULL)
802                                 return -ENOMEM;
803
804                         TRACE_PS("add client %d to client list", pid_nr(pid));
805                         spin_lock_init(&pClient->lock);
806                         pClient->sig_flags = arg;
807                         pClient->pid = get_pid(pid);
808                         pClient->next = pInfo->firstClient;
809                         pClient->first_msg = NULL;
810                         pClient->last_msg = NULL;
811                         pClient->next_block_to_read = NULL;
812                         pClient->msg_count = 0;
813                         pInfo->firstClient = pClient;
814                 }
815         }
816
817         return 0;
818 }
819
820 static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
821                          unsigned char __user * buf)
822 {
823         struct r3964_client_info *pClient;
824         struct r3964_block_header *block;
825
826         if (!buf) {
827                 return -EINVAL;
828         }
829
830         pClient = findClient(pInfo, pid);
831         if (pClient == NULL) {
832                 return -EINVAL;
833         }
834
835         block = pClient->next_block_to_read;
836         if (!block) {
837                 return 0;
838         } else {
839                 if (copy_to_user(buf, block->data, block->length))
840                         return -EFAULT;
841
842                 remove_client_block(pInfo, pClient);
843                 return block->length;
844         }
845
846         return -EINVAL;
847 }
848
849 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
850                 int error_code, struct r3964_block_header *pBlock)
851 {
852         struct r3964_message *pMsg;
853         unsigned long flags;
854
855         if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
856 queue_the_message:
857
858                 pMsg = kmalloc(sizeof(struct r3964_message),
859                                 error_code ? GFP_ATOMIC : GFP_KERNEL);
860                 TRACE_M("add_msg - kmalloc %p", pMsg);
861                 if (pMsg == NULL) {
862                         return;
863                 }
864
865                 spin_lock_irqsave(&pClient->lock, flags);
866
867                 pMsg->msg_id = msg_id;
868                 pMsg->arg = arg;
869                 pMsg->error_code = error_code;
870                 pMsg->block = pBlock;
871                 pMsg->next = NULL;
872
873                 if (pClient->last_msg == NULL) {
874                         pClient->first_msg = pClient->last_msg = pMsg;
875                 } else {
876                         pClient->last_msg->next = pMsg;
877                         pClient->last_msg = pMsg;
878                 }
879
880                 pClient->msg_count++;
881
882                 if (pBlock != NULL) {
883                         pBlock->locks++;
884                 }
885                 spin_unlock_irqrestore(&pClient->lock, flags);
886         } else {
887                 if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
888                     && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
889                         pClient->last_msg->arg++;
890                         TRACE_PE("add_msg - inc prev OVERFLOW-msg");
891                 } else {
892                         msg_id = R3964_MSG_ACK;
893                         arg = 0;
894                         error_code = R3964_OVERFLOW;
895                         pBlock = NULL;
896                         TRACE_PE("add_msg - queue OVERFLOW-msg");
897                         goto queue_the_message;
898                 }
899         }
900         /* Send SIGIO signal to client process: */
901         if (pClient->sig_flags & R3964_USE_SIGIO) {
902                 kill_pid(pClient->pid, SIGIO, 1);
903         }
904 }
905
906 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
907                                         struct r3964_client_info *pClient)
908 {
909         struct r3964_message *pMsg = NULL;
910         unsigned long flags;
911
912         if (pClient->first_msg) {
913                 spin_lock_irqsave(&pClient->lock, flags);
914
915                 pMsg = pClient->first_msg;
916                 pClient->first_msg = pMsg->next;
917                 if (pClient->first_msg == NULL) {
918                         pClient->last_msg = NULL;
919                 }
920
921                 pClient->msg_count--;
922                 if (pMsg->block) {
923                         remove_client_block(pInfo, pClient);
924                         pClient->next_block_to_read = pMsg->block;
925                 }
926                 spin_unlock_irqrestore(&pClient->lock, flags);
927         }
928         return pMsg;
929 }
930
931 static void remove_client_block(struct r3964_info *pInfo,
932                                 struct r3964_client_info *pClient)
933 {
934         struct r3964_block_header *block;
935
936         TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
937
938         block = pClient->next_block_to_read;
939         if (block) {
940                 block->locks--;
941                 if (block->locks == 0) {
942                         remove_from_rx_queue(pInfo, block);
943                 }
944         }
945         pClient->next_block_to_read = NULL;
946 }
947
948 /*************************************************************
949  * Line discipline routines
950  *************************************************************/
951
952 static int r3964_open(struct tty_struct *tty)
953 {
954         struct r3964_info *pInfo;
955
956         TRACE_L("open");
957         TRACE_L("tty=%p, PID=%d, disc_data=%p",
958                 tty, current->pid, tty->disc_data);
959
960         pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
961         TRACE_M("r3964_open - info kmalloc %p", pInfo);
962
963         if (!pInfo) {
964                 printk(KERN_ERR "r3964: failed to alloc info structure\n");
965                 return -ENOMEM;
966         }
967
968         pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
969         TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
970
971         if (!pInfo->rx_buf) {
972                 printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
973                 kfree(pInfo);
974                 TRACE_M("r3964_open - info kfree %p", pInfo);
975                 return -ENOMEM;
976         }
977
978         pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
979         TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
980
981         if (!pInfo->tx_buf) {
982                 printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
983                 kfree(pInfo->rx_buf);
984                 TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
985                 kfree(pInfo);
986                 TRACE_M("r3964_open - info kfree %p", pInfo);
987                 return -ENOMEM;
988         }
989
990         spin_lock_init(&pInfo->lock);
991         pInfo->tty = tty;
992         init_waitqueue_head(&pInfo->read_wait);
993         pInfo->priority = R3964_MASTER;
994         pInfo->rx_first = pInfo->rx_last = NULL;
995         pInfo->tx_first = pInfo->tx_last = NULL;
996         pInfo->rx_position = 0;
997         pInfo->tx_position = 0;
998         pInfo->last_rx = 0;
999         pInfo->blocks_in_rx_queue = 0;
1000         pInfo->firstClient = NULL;
1001         pInfo->state = R3964_IDLE;
1002         pInfo->flags = R3964_DEBUG;
1003         pInfo->nRetry = 0;
1004
1005         tty->disc_data = pInfo;
1006         tty->receive_room = 65536;
1007
1008         setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo);
1009
1010         return 0;
1011 }
1012
1013 static void r3964_close(struct tty_struct *tty)
1014 {
1015         struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1016         struct r3964_client_info *pClient, *pNext;
1017         struct r3964_message *pMsg;
1018         struct r3964_block_header *pHeader, *pNextHeader;
1019         unsigned long flags;
1020
1021         TRACE_L("close");
1022
1023         /*
1024          * Make sure that our task queue isn't activated.  If it
1025          * is, take it out of the linked list.
1026          */
1027         del_timer_sync(&pInfo->tmr);
1028
1029         /* Remove client-structs and message queues: */
1030         pClient = pInfo->firstClient;
1031         while (pClient) {
1032                 pNext = pClient->next;
1033                 while (pClient->msg_count) {
1034                         pMsg = remove_msg(pInfo, pClient);
1035                         if (pMsg) {
1036                                 kfree(pMsg);
1037                                 TRACE_M("r3964_close - msg kfree %p", pMsg);
1038                         }
1039                 }
1040                 put_pid(pClient->pid);
1041                 kfree(pClient);
1042                 TRACE_M("r3964_close - client kfree %p", pClient);
1043                 pClient = pNext;
1044         }
1045         /* Remove jobs from tx_queue: */
1046         spin_lock_irqsave(&pInfo->lock, flags);
1047         pHeader = pInfo->tx_first;
1048         pInfo->tx_first = pInfo->tx_last = NULL;
1049         spin_unlock_irqrestore(&pInfo->lock, flags);
1050
1051         while (pHeader) {
1052                 pNextHeader = pHeader->next;
1053                 kfree(pHeader);
1054                 pHeader = pNextHeader;
1055         }
1056
1057         /* Free buffers: */
1058         wake_up_interruptible(&pInfo->read_wait);
1059         kfree(pInfo->rx_buf);
1060         TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
1061         kfree(pInfo->tx_buf);
1062         TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
1063         kfree(pInfo);
1064         TRACE_M("r3964_close - info kfree %p", pInfo);
1065 }
1066
1067 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
1068                           unsigned char __user * buf, size_t nr)
1069 {
1070         struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1071         struct r3964_client_info *pClient;
1072         struct r3964_message *pMsg;
1073         struct r3964_client_message theMsg;
1074         DECLARE_WAITQUEUE(wait, current);
1075
1076         int count;
1077
1078         TRACE_L("read()");
1079
1080         pClient = findClient(pInfo, task_pid(current));
1081         if (pClient) {
1082                 pMsg = remove_msg(pInfo, pClient);
1083                 if (pMsg == NULL) {
1084                         /* no messages available. */
1085                         if (file->f_flags & O_NONBLOCK) {
1086                                 return -EAGAIN;
1087                         }
1088                         /* block until there is a message: */
1089                         add_wait_queue(&pInfo->read_wait, &wait);
1090 repeat:
1091                         __set_current_state(TASK_INTERRUPTIBLE);
1092                         pMsg = remove_msg(pInfo, pClient);
1093                         if (!pMsg && !signal_pending(current)) {
1094                                 schedule();
1095                                 goto repeat;
1096                         }
1097                         __set_current_state(TASK_RUNNING);
1098                         remove_wait_queue(&pInfo->read_wait, &wait);
1099                 }
1100
1101                 /* If we still haven't got a message, we must have been signalled */
1102
1103                 if (!pMsg)
1104                         return -EINTR;
1105
1106                 /* deliver msg to client process: */
1107                 theMsg.msg_id = pMsg->msg_id;
1108                 theMsg.arg = pMsg->arg;
1109                 theMsg.error_code = pMsg->error_code;
1110                 count = sizeof(struct r3964_client_message);
1111
1112                 kfree(pMsg);
1113                 TRACE_M("r3964_read - msg kfree %p", pMsg);
1114
1115                 if (copy_to_user(buf, &theMsg, count))
1116                         return -EFAULT;
1117
1118                 TRACE_PS("read - return %d", count);
1119                 return count;
1120         }
1121         return -EPERM;
1122 }
1123
1124 static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
1125                            const unsigned char *data, size_t count)
1126 {
1127         struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1128         struct r3964_block_header *pHeader;
1129         struct r3964_client_info *pClient;
1130         unsigned char *new_data;
1131
1132         TRACE_L("write request, %d characters", count);
1133 /* 
1134  * Verify the pointers 
1135  */
1136
1137         if (!pInfo)
1138                 return -EIO;
1139
1140 /*
1141  * Ensure that the caller does not wish to send too much.
1142  */
1143         if (count > R3964_MTU) {
1144                 if (pInfo->flags & R3964_DEBUG) {
1145                         TRACE_L(KERN_WARNING "r3964_write: truncating user "
1146                                 "packet from %u to mtu %d", count, R3964_MTU);
1147                 }
1148                 count = R3964_MTU;
1149         }
1150 /*
1151  * Allocate a buffer for the data and copy it from the buffer with header prepended
1152  */
1153         new_data = kmalloc(count + sizeof(struct r3964_block_header),
1154                         GFP_KERNEL);
1155         TRACE_M("r3964_write - kmalloc %p", new_data);
1156         if (new_data == NULL) {
1157                 if (pInfo->flags & R3964_DEBUG) {
1158                         printk(KERN_ERR "r3964_write: no memory\n");
1159                 }
1160                 return -ENOSPC;
1161         }
1162
1163         pHeader = (struct r3964_block_header *)new_data;
1164         pHeader->data = new_data + sizeof(struct r3964_block_header);
1165         pHeader->length = count;
1166         pHeader->locks = 0;
1167         pHeader->owner = NULL;
1168
1169         pClient = findClient(pInfo, task_pid(current));
1170         if (pClient) {
1171                 pHeader->owner = pClient;
1172         }
1173
1174         memcpy(pHeader->data, data, count);     /* We already verified this */
1175
1176         if (pInfo->flags & R3964_DEBUG) {
1177                 dump_block(pHeader->data, count);
1178         }
1179
1180 /*
1181  * Add buffer to transmit-queue:
1182  */
1183         add_tx_queue(pInfo, pHeader);
1184         trigger_transmit(pInfo);
1185
1186         return 0;
1187 }
1188
1189 static int r3964_ioctl(struct tty_struct *tty, struct file *file,
1190                 unsigned int cmd, unsigned long arg)
1191 {
1192         struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1193         if (pInfo == NULL)
1194                 return -EINVAL;
1195         switch (cmd) {
1196         case R3964_ENABLE_SIGNALS:
1197                 return enable_signals(pInfo, task_pid(current), arg);
1198         case R3964_SETPRIORITY:
1199                 if (arg < R3964_MASTER || arg > R3964_SLAVE)
1200                         return -EINVAL;
1201                 pInfo->priority = arg & 0xff;
1202                 return 0;
1203         case R3964_USE_BCC:
1204                 if (arg)
1205                         pInfo->flags |= R3964_BCC;
1206                 else
1207                         pInfo->flags &= ~R3964_BCC;
1208                 return 0;
1209         case R3964_READ_TELEGRAM:
1210                 return read_telegram(pInfo, task_pid(current),
1211                                 (unsigned char __user *)arg);
1212         default:
1213                 return -ENOIOCTLCMD;
1214         }
1215 }
1216
1217 static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
1218 {
1219         TRACE_L("set_termios");
1220 }
1221
1222 /* Called without the kernel lock held - fine */
1223 static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
1224                         struct poll_table_struct *wait)
1225 {
1226         struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1227         struct r3964_client_info *pClient;
1228         struct r3964_message *pMsg = NULL;
1229         unsigned long flags;
1230         int result = POLLOUT;
1231
1232         TRACE_L("POLL");
1233
1234         pClient = findClient(pInfo, task_pid(current));
1235         if (pClient) {
1236                 poll_wait(file, &pInfo->read_wait, wait);
1237                 spin_lock_irqsave(&pInfo->lock, flags);
1238                 pMsg = pClient->first_msg;
1239                 spin_unlock_irqrestore(&pInfo->lock, flags);
1240                 if (pMsg)
1241                         result |= POLLIN | POLLRDNORM;
1242         } else {
1243                 result = -EINVAL;
1244         }
1245         return result;
1246 }
1247
1248 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1249                         char *fp, int count)
1250 {
1251         struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1252         const unsigned char *p;
1253         char *f, flags = 0;
1254         int i;
1255
1256         for (i = count, p = cp, f = fp; i; i--, p++) {
1257                 if (f)
1258                         flags = *f++;
1259                 if (flags == TTY_NORMAL) {
1260                         receive_char(pInfo, *p);
1261                 } else {
1262                         receive_error(pInfo, flags);
1263                 }
1264
1265         }
1266 }
1267
1268 MODULE_LICENSE("GPL");
1269 MODULE_ALIAS_LDISC(N_R3964);